Vaccines: Side Effects and Concerns
How do Covid-19 vaccines work? When the vaccine is injected, it activates the innate immune response with “watchdog” cells macrophages, and dendritic cells that screen the blood for suspicious signs. The former eats up dead cells and the latter collects information about the unwanted intruder and informs the adaptive immune system (producing antibodies). The cells, when they sense danger; release a group of proteins called cytokines which act on blood vessels to make them wider and helps deliver other immune cells for backup. The innate immune response unfolds over a few hours to days and may sometimes result in flu-like symptoms like headache, fever, muscle, and joint pain, or swelling and pain at the vaccination site. These side effects are designed to aid immune response and are a healthy sign that the immune system is working. These symptoms subside in a day or two because the body’s response to vaccination is self-limiting. For eg, the body only makes as much spike protein as the...